Technical Field
Embodiments disclosed herein relates to communications within an optical network, and in particular, to methods and apparatus for multiplexing data signals.
Description of the Related Art
With the exponential growth in communications, there is a continuing demand for increased capacity. Generally, expanding capacity of fiber optic systems has been achieved by installing more cables; increasing system bitrate; and by wavelength division multiplexing.
Wavelength division multiplexing (WDM) uses existing electronics and fibers, and simply shares fibers by transmitting different channels at different wavelengths. Generally, a wavelength division multiplexing (WDM) system uses a multiplexer at the transmitter to join optical signals together and a demultiplexer at the receiver to split them apart. Most wavelength division multiplexing (WDM) systems operate on single-mode fiber optical cables, which have a core diameter of 9 μm. One type of wavelength division multiplexing (WDM) system is referred to as a “coarse wavelength division multiplexing (CWDM)” system. Generally, coarse wavelength division multiplexing (CWDM) systems provide up to eight (8) or nine (9) communications channels. Coarse wavelength division multiplexing (CWDM) uses increased channel spacing (spacing between wavelength groupings) to permit use of less sophisticated transceiver equipment.
Unfortunately, with the ever increasing demand for bandwidth, this is not adequate. As cable installation is a laborious and costly process, it is desirable to increase signal transmission using existing infrastructure. Thus, what are needed are methods and apparatus to increase signal transmission over existing implementations of fiber optics.